The time dependant color-changing process or function employed in all of the embodiments described herein is a well-known technology. In particular there are numerous patents issued to the inventors herein relevant to self expiring passes and parking permits. Examples of these products and the technology used by these products are represented by the Haas patents, e.g., U.S. Pat. Nos. 5,364,132; 5,446,705; 5,602,804; 5,715,215; 5,873,606; 5,719,828; 5,785,354; 5,822,280; 5,930,206; and 5,957,458. These products have become universally accepted as the means for controlling and improving visitor security and temporary badges, and are generally self-expiring visitor badges, which change color, and show an “expired” indicia after the predetermined authorization time has lapsed.
These prior art tags are typically formed from two parts that must be joined together to activate the color-changing process. This renders the tags difficult to work with. A need exists for a simple single piece self-expiring tag.